Attacks are reminder of Colombia oil risks: UpdateOREANDA-NEWS. February 10, 2016. An attack yesterday morning on a military installation in Colombia?s oil-producing eastern province of Arauca highlights the threat posed by the country second largest rebel group ELN, despite advanced peace talks with the main rebel group Farc.

Two more attacks occurred since then, state-controlled Ecopetrol told Argus. Last night the Cao Limn-Coveas crude pipeline was bombed "by an unknown third party" at La Caaguata, Cubar municipality, in Boyac province. The second attack occurred in Guamalito, Arauquita municipality, in Arauca province. Ecopetrol says it has activated a contingency plan and suspended pumping on the line.

ELN, estimated to encompass around 2,000 fighters, is based close to the Colombia-Venezuela border, including oil and mining areas in Casanare, Arauca and Norte de Santander provinces.

Colombia's military attributed yesterday attack on its Arauca installation to the ELN, which is widely seen as more ideological than the Farc.

The ELN has been engaged in exploratory talks with the Santos government for more than a year in Ecuador, but the two sides have yet to open formal peace negotiations.

"The ELN is mistaken if it believes that its attacks help to pave the road to peace. I've ordered an escalation of operations against this guerrilla group," president Juan Manuel Santos said yesterday before the pipeline attacks.

The group has regularly targeted oil personnel, facilities and oil pipelines in a quixotic aspiration to cast off private-sector investment in the development of Colombia?s natural resources.

US independent Occidental operates the 65,000 b/d Cao Limn oil complex in Arauca, and depends on Ecopetrol's 220,000 b/d Cao Limn-Coveas pipeline to dispatch the crude to the Caribbean coast for export.

The Cao Limn-Coveas pipeline is a regular ELN target.

Before yesterday?s twin attacks, the line apparently had not been hit since a 4 November 2015 strike in Cubar? municipality, Boyac? province. That attack did not rupture the line.

Ecopetrol was forced to take the line out of service on 26 January this year in order to repair an illicit valve.

The company?s 85,000 b/d Transandino pipeline was last attacked on 24 June 2015, but remained off line into late last year for separate illicit valve repairs.

Colombia's defense ministry reported 80 attacks on pipelines in 2015, down by 43pc from 141 in 2014. Most of the attacks were concentrated in the months of June and July when a unilateral cease-fire declared by Farc broke down.

Total attacks on infrastructure, including pipelines, transmission towers, roads and bridges, fell to 129 in 2015, down by 38pc from 208 the year before.

Attacks spiked to 405 in 2013 after falling steadily throughout former president Alvaro Uribe's presidency (2002-2010).

President Juan Manuel Santos' administration has been negotiating with Farc rebels since 2012 in Havana, Cuba where the two sides have pledged to sign a deal by 23 March.

The Farc has not targeted pipeline infrastructure since it declared a cease-fire in July last year.

The two sides are negotiating final items on the agenda, including demobilization of rebel fighters and the terms for a bilateral cease fire.

Responding to a government request, the UN Security Council last month agreed to monitor the ceasefire and demobilization should the parties reach a final peace deal.

ELN's persistent aggression suggests that the government is resisting that rebel group's demands to negotiate certain points, like energy and mining policy, conflict analysts tell Argus.